Restless Fortress

Restless Fortress enters tapped.
{T}: Add {W} or {B}.
{2}{W}{B}: Restless Fortress becomes a 1/4 white and black Nightmare creature until end of turn. It's still a land.
Whenever Restless Fortress attacks, defending player loses 2 life and you gain 2 life.

Putrid Warrior

Whenever Putrid Warrior deals damage, choose one —
• Each player loses 1 life.
• Each player gains 1 life.

Congregate

Target player gains 2 life for each creature on the battlefield.

Indulging Patrician

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of your end step, if you gained 3 or more life this turn, each opponent loses 3 life.

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Cliffhaven Vampire

Flying
Whenever you gain life, each opponent loses 1 life.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Swamp

Orzhov Guildmage

{2}{W}: Target player gains 1 life.
{2}{B}: Each player loses 1 life.

Healing Hands

Rest for the Weary

Target player gains 4 life.
Landfall — If you had a land enter the battlefield under your control this turn, that player gains 8 life instead.

Zof Bloodbog

Zof Bloodbog enters tapped.
{T}: Add {B}.

Zof Consumption

Each opponent loses 4 life and you gain 4 life.

Zof Consumption // Zof Bloodbog

Cleric Class

(Gain the next level as a sorcery to add its ability.)
If you would gain life, you gain that much life plus 1 instead.
{3}{W}: Level 2
Whenever you gain life, put a +1/+1 counter on target creature you control.
{4}{W}: Level 3
When this Class becomes level 3, return target creature card from your graveyard to the battlefield. You gain life equal to that creature's toughness.

Tempt with Treats

Create a Food token. (Then exile this card. You may cast the creature later from exile.)

Gumdrop Poisoner

Lifelink
When Gumdrop Poisoner enters, up to one target creature gets -X/-X until end of turn, where X is the amount of life you gained this turn.

Gumdrop Poisoner // Tempt with Treats

False Cure

Until end of turn, whenever a player gains life, that player loses 2 life for each 1 life they gained.

Moon-Blessed Cleric

Divine Intervention — When Moon-Blessed Cleric enters, you may search your library for an enchantment card, reveal it, then shuffle and put that card on top.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Heliod's Intervention

Choose one —
• Destroy X target artifacts and/or enchantments.
• Target player gains twice X life.

Angel of Destiny

Flying, double strike
Whenever a creature you control deals combat damage to a player, you and that player each gain that much life.
At the beginning of your end step, if you have at least 15 life more than your starting life total, each player Angel of Destiny attacked this turn loses the game.

Devour Flesh

Target player sacrifices a creature, then gains life equal to that creature's toughness.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Scoured Barrens

Scoured Barrens enters tapped.
When Scoured Barrens enters, you gain 1 life.
{T}: Add {W} or {B}.

Tainted Remedy

If an opponent would gain life, that player loses that much life instead.

Plains

Bloodbond Vampire

Whenever you gain life, put a +1/+1 counter on Bloodbond Vampire.

Blind Obedience

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Artifacts and creatures your opponents control enter tapped.

Beacon of Immortality

Double target player's life total. Shuffle Beacon of Immortality into its owner's library.

Liliana, Defiant Necromancer

+2: Each player discards a card.
−X: Return target nonlegendary creature card with mana value X from your graveyard to the battlefield.
−8: You get an emblem with "Whenever a creature dies, return it to the battlefield under your control at the beginning of the next end step."

Liliana, Heretical Healer

Lifelink
Whenever another nontoken creature you control dies, exile Liliana, Heretical Healer, then return her to the battlefield transformed under her owner's control. If you do, create a 2/2 black Zombie creature token.

Liliana, Heretical Healer // Liliana, Defiant Necromancer

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Alms Beast

Creatures blocking or blocked by Alms Beast have lifelink.

Knight of Dawn's Light

First strike
If you would gain life, you gain that much life plus 1 instead.
{1}{W}: Knight of Dawn's Light gets +1/+1 until end of turn.